Insulated pipe

ABSTRACT

Pipes or pipelines insulated on their surface or surfaces are described. The pipes or pipelines may be for submerged service, below the surface of water. The insulation chosen may be an epoxy substantially free of phenolics and one or more of glass or ceramics. The coating may be an abrasion resistant coating. Such pipes or pipelines are generally intended for the transport of fluids, which can include natural gas, natural gas liquids, crude oil, refined products, chemicals, combinations thereof, and the like.

[0001] This application claims the benefit of U.S. ProvisionalApplication Ser. No. 60/142,340, filed Jul. 2, 1999. Further, thisapplication claims benefit of U.S. Provisional Application Ser. No.60/304,175, filed Nov. 12, 1999. Still further, this application claimsthe benefit of and is a Continuation-in-Part of regular U.S. ApplicationSer. No. 09/605,112 filed Jun. 28, 2000. Such benefit is provided under37 CFR § 1.78 (a)(3) and 35 USC § 120.

TECHNICAL FIELD

[0002] This invention relates generally to pipe coating. Morespecifically, embodiments of this invention relate to insulation strataincluding a layer or layers in each strata, on a pipe's circumference,where such layers may be abrasion resistant, corrosion resistant andprovide thermal insulation to the pipe's contents. The insulation may beplaced on a pipe's exterior circumference or surface, interiorcircumference or surface, or both. The pipe or a pipeline including thepipe, is intended for use in fluid transport, generally submerged.

DESCRIPTION INTRODUCTION

[0003] Embodiments of my invention concern certain pipe insulation andpipe coatings.

[0004] In embodiments of my invention, the insulation strata may beapplied to the interior or exterior circumference or surface of pipes orpipelines, or both the interior and exterior circumferences or surfaces.At least a first strata of insulation may be applied to the pipe surfacepreceded by an optional primer, a second strata applied to the firststrata and optionally at least a first layer of an abrasion resistantcoating may be applied to the second insulation strata.

[0005] In other embodiments of the present invention the firstinsulation strata may include a Ceramic-Cover™ 100, (manufactured)Therma-Cote Inc. of Atlanta, Ga., USA and may be described as a viscoussolution of ceramic and acrylic latex. Or the first insulation stratamay include Therma-Coat from Hempel Coatings, Conroe, Tex. The topcoator abrasion resistant coating, EC-376F, may be manufactured byIndustrial Environmental Coatings Corp of Pompano Beach, Fla.

[0006] A second strata may include one or more of syntactic plasticfoam, such as polyethylene, polypropylene, polyurethane, and the like,and such syntactic foams may include discrete hollow or porous particlesformed from another material. Such second strata may be formed in one ormore layers.

[0007] Embodiments of this invention further include certain methods ofapplying the insulation strata and the optional coating. Alsocontemplated are pipes and pipelines coated, on the interiorcircumference and/or surface, exterior circumference and/or surface, orboth, with an optional primer, with the insulation strata and/or theabrasion resistant coating. In an embodiment with both internal andexternal insulation, the interior and exterior may be the same ordifferent in thickness, number of layers, materials used and the like.The insulation strata and optional abrasion resistant coatings haveproperties rendering them superior to, and unique from, previouslyavailable pipe insulation and coating. The pipe insulation and optionalabrasion resistant coatings described herein are suited for use inproducing certain classes of insulated, submerged or buried pipes orpipelines. Those skilled in the art will appreciate that numerousmodifications to these embodiments can be made without departing fromthe scope of the invention. For example, although gas and crude oilpipes and pipelines, insulated on their interior or exterior, arediscussed herein, the insulated pipelines may be made using combinationsof other coatings and other surfaces to be coated. To the extent mydescription is specific, it is solely for the purpose of illustratingembodiments of my invention and should not be taken as limiting thepresent invention to these embodiments. Definition of Terms and Tests:Density: ASTM D-793 Compressive Strength: ASTM D-1621 R value, ThermalResistance ASTM C-177-85 k, Thermal Conductance ASTM C-158 Adhesion toSteel ASTM D-4541

[0008] Primer

[0009] A water and chemical resistant primer may optionally be applieddirectly to the surface of the pipe being insulated, between the pipeand a first layer of insulation. When a pipeline is installed offshoreon the seafloor it may have high spots and low spots due to theundulation of the seafloor. In the low spots water may accumulate on theinterior of the pipe. This water may come from hydrostatic testing ofthe pipeline or water entrained in the fluids carried by the pipeline.Such water may cause corrosion, called “6o'clock” corrosion, for itslocation on the bottom of a pipeline as one would view a cross section.Should water penetrate the layers of insulation and the topcoat on theinterior of the pipe, it could cause corrosion, resulting perhaps in aleak. Particularly troublesome is the presence of carbonic acid orhydrochloric acid in the water. Occasionally oil and gas will containsmall amounts of corrosive gases such as carbon dioxide or hydrogensulfide.

[0010] When either of these gases are dissolved in water, acid iscreated that may attack the surface of the pipe possibly causing failureof the pipe. The use of a primer between an insulation layer and thesteel pipe surface may mitigate such a problem. Many types of primersare available and will be known to those of ordinary skill in the art,one type is a phenolic primer such as EP-10, which is manufactured byMorton (Reading, Pa.). This primer may be applied at a thickness thatmay average 1 mil and may be cured in an oven at 300° F. for one hour.Other primers may be used, some of these primers may not require ovencuring, but may be air cured.

[0011] Insulation

[0012] The insulation of embodiments of my invention will include atleast a first strata generally the closest of the strata to the pipe, ofat least two layers and optionally a second strata of insulation, thesecond strata being at least one layer, wherein the first strata will bepositioned between the pipe and the second strata.

[0013] First Strata

[0014] In embodiments of the present invention, the first insulationstrata may include a Ceramic-Cover® 100 (CC-100), manufacturedTherma-Cote Inc. of Atlanta, Georgia, USA, or the first insulationstrata may include Therma-Coat coating manufactured by Hempel Coatings,referred to above. Combinations of any such materials are alsocontemplated. Polyurethane foam (PU), may have a heat or thermalconductance (k) from 0.65 to 0.1 BTU/sq. ft., hr., F°. The conductanceof the insulation of embodiments of my invention will be ≦0.4 BTU/sq.ft. hr F°, or ≦0.3 BTU/sq. ft. hr F°, or ≦0.08 BTU/sq. ft. hr F°, or≦0.07 BTU/sq. ft. hr F°, or ≦0.06 BTU/sq. ft. hr F°, or ≧0.05 BTU/sq.ft. hr F°, or ≦0.04 BTU/sq. ft. hr F°, or ≦0.03 BTU/sq. ft. hr F°, or≦0.02 BTU/sq. ft. hr F°, or≧0.001 BTU/sq. ft. hr F°, or ≧0.003 BTU/sq.ft. hr F°, or ≧0.005 BTU/sq. ft. hr F°. The density of the first stratainsulation, excluding the fibrous or non-woven material discussedherein, as determined by ASTM D-792, may be ≧0.1 g/cm³, or ≧0.2 g/cm³,or ≧0.3 g/cm³, or ≧0.35 g/cm³, or ≧0.95 g/cm³, or ≧0.75 g/cm³, or ≦0.65g/cm³-, or ≦0.55 g/cm³. The density of common rigid urethane foams is inthe range of 0.012-0.025 g/cm³. The compressive strength of the firststrata insulation of embodiments of my invention, may be ≧100 psi, or≧200 psi, or ≧400 psi , or ≧800 psi, or ≧1500 psi, or ≧2,000 psi, or≧2500 psi or ≧3000 psi, or ≧3500 psi, or ≧4000 psi. The compressivestrength of rigid urethane foams is in the range of 15-60 psi (10%deflection).

[0015] The first insulation strata may be characterized by its R value(Thermal resistance °F. hr ft² /BTU) per applied inch. Other types ofinsulation typically have Thermal resistance as follows: cork boardtypically has an insulation value of about 3.33 R value per inch; rockcork about 3.9 R value per inch; expanded polystyrene about 3.0 R valueper inch; and polyurethane foam 5-9 R value per inch. Such other typesof insulation may be utilized in the second insulation strata. The firstinsulation strata of embodiments of the present invention may be ≧5 Rvalue per inch, or ≧10 R value per inch, or ≧12, or ≧14 R value perinch, or ≧25 R value per inch, or ≧35 R value per inch, or ≧40 R valueper inch, or ≧45 R value per inch, or ≧50 R value per inch, or ≧60 Rvalue per inch or ≦400 R value per inch, or ≦300 R value per inch, or≦200 R value per inch, or ≦150 R value per inch, or ≦125 R value perinch. Other insulation materials for the first strata are contemplatedas long as it provides the insulation values stated herein.

[0016] Adhesion to steel, of the first strata insulation of embodimentsof my invention, as determined by ASTM D-4541, may be ≧1000 psi, or≧1500 psi, or ≧1700 psi, or ≧1800 psi, or ≧2000 psi, or ≧2200 psi, or≧2300 psi.

[0017] The CC-100 insulation is described by its manufacturer(Therma-Cote) as a proprietary viscous solution of ceramic and acryliclatex. The insulation is also described as an 84% solid latex, highdensity material. The ceramic portion of the CC-100 insulation isdescribed as an asymmetrical particle, of amorphous shape. Such a shapeis substantially non-spheroidal. However, I also contemplate spheres orspheroidal shapes for the ceramic insulation. Further contemplated aspart of the first strata insulation are a layer or layers of fabric orfibers, woven or non-woven of polymeric or inorganic materials. Suchmaterials may be made from carbon fibers, silica fibers, glass fibers,polyethylene fibers or fabrics, polypropylene fibers or fabrics,polyphenylene sulfide fibers or fabrics, glass wool, mineral wool, cork,rock cork, polystyrene. The first insulation strata may also containglass microspheres. The ceramic or glass portion of the CC-100insulation will be ≧5% (volume), or ≧7%, or ≧9%, or ≦25%, or ≦20%, or≦15%. These volumetric measurements are after substantially all of thevolatiles and/or evaporative ingredients have been removed.

[0018] The Therma-Coat insulation is characterized by its manufacturer(Hempel) as a high solids epoxy, 84+% solids (volume) and/or 86+% solidsby weight. The Therma-Coat insulation is substantially free ofphenolics. By substantially free of phenolics, I intend that ≦5 weightpercent, or ≦3 weight percent, or ≦1 weight percent, or 0 percent of thehigh solids epoxy will be phenolics. This substantial freedom ofphenolics relates to the first insulation strata of embodiments of myinvention and not to the optional primer or optional top coat, which mayinclude phenolics. The Therma-Coat (Hempel) insulation may usemicrospheres of glass, ceramic spheres, amorphous ceramic or glassshapes, spheroidal ceramic or glass shapes, non-spheroidal ceramic orglass shapes, or combinations thereof. The ratio of glass to ceramics inthe organic matrix, after volatilization and/or evaporation may be 10:90to 90:10 or 20:80 to 80:20, or 30:70 to 70:30, or 40:60 to 60:40. Theratio of both glass and ceramic to the organic components, aftervolatilization and/or evaporation may be 10:90 to 90:10, or 20:80 to80:20, or 30:70 to 70:30, or 40:60 to 60:40. The insulation may beapplied by any conventional method, such as rolling, brushing,troweling, extruding or spraying. In a typical installation, theinsulation, first and second strata, will be applied to the interiorsurfaces or circumferences of the pipe, the exterior surface orcircumference of the pipe, or both. Optionally, a primer will be placeddirectly on the pipe surface or surfaces, followed by the firstinsulation strata described herein.

[0019] While the manufacturers of these products state that no specificsurface preparation may be necessary, the surface may be prepared, bymethods known to those of ordinary skill in the art, to reduce oreliminate any oils, dirt, or other potential contaminants on a pipe'ssurface or surfaces, that might affect the adhesion or insulationperformance of the applied combination of insulation and abrasionresistant coating.

[0020] In application of this first insulation strata to a pipe, afteroptional surface preparation, and after an optional primer layer orlayers applied and the insulation applied, an optional abrasionresistant coating be applied after the insulation layer or layers havecured.

[0021] The surface roughness or smoothness of steel pipes is generally0.0018 inches, while the insulation described herein is generally≦0.0006 inches, or ≦0.0004 inches, or ≦0.0002 inches, or ≦0.0001 inches,or ≦0.00009 inches. The insulation will also provide corrosionprotection to the surface or surfaces to which it is applied.

[0022] The surface temperature of the pipe upon which the insulation maybe ambient or up to 150° F. Application in the range of from 32° F. to460° F. is also contemplated.

[0023] Applications of the first insulation strata may be at a totalthickness of ≧2 mils, or ≧5mils, or ≧10 mils, or ≧20mils, or ≧25 mils,or ≦100 mils, or ≦90 mils or ≦85 mils. Or in other embodiments of myinvention, the first insulation strata can be applied in one coat at ≧2mils or ≧5 mils, or ≧10 mils or ≧15 mils, or ≧25 mils, or ≦60 mils, or≦50 mils or ≦40 mils thickness, or in several coats or layers, 2, 3, 4,5, 6, 7, 8, 9, 10 or more layers, to these total thicknesses. The layersmay be the same thickness or different.

[0024] Another insulating material that may be used for this firststrata is a product known as Super-Therm®. Super-Therm® is a ceramiccoating that is said to utilize three types ceramic particles to achieveresults. Two of the ceramics are said to reflect heat and the third issaid to prevent heat loss by conduction. It is said by the manufacturerto be made with two acrylics and one urethane. It completely cures in7-10 days and may be applied within a temperature range of 40° F. up to110° F. Hot Box Testing indicates that this material to be a thermalresistor that is said to be as effective as fiberglass with anequivalent rating of RI 9 (per inch). Thermal Conductivity of thismaterial has been tested with a reported range from 0.00543 watts/cm °K.up to 0.00640 watts/cm °K. Insulation coefficients are reported by themanufacturer to be 0.13 BTU/ft2 hr F° or in metric terms-−0.019 metricwatts/meter kelvin°.

[0025] Another insulation product that may also be used where theinsulation value is provided by hollow glass (micro)spheres. Thisproduct is called Biotherm® 453 and is manufactured by TFT of Houston,Tex. This material is said by its manufacturer to be a primarily epoxyresin with proprietary polyamines. It is further said to have lowvolatile organic compounds (VOC's) and is normally trowel applied butmay be spray applied.

[0026] The use of the insulation layer or layers, without the use of atopcoat, is also contemplated, such insulation-only applications mayinclude the optional primer.

[0027] The first strata can include the above embodiments, and mayfurther include other materials. Such other materials (referred to belowas (G)) include, but are not limited to fiberglass matting, fiberglassfabric or roving, rock wool, rock cork, mineral wool, silica fiber tape,carbon fiber tape, fumed silica, polyphenylene sulfide, polyphenyleneoxide fibers and fabrics made from these materials as well as non-wovenfabrics or matting and the like. Such materials may be alternated withthe material or materials described above, or can be used in anon-symmetric manner with the application of the matrix and containedparticles (referred to below as H). By non-symmetric I intend 1, 2, 3,4, 5 or more layers of matrix and particles may be applied, followed byone or more layers of other materials such as fiberglass matting,fabric, strands or roving, rock wool, mineral wool, silica fiber tape,carbon fiber tape, fumed silica, polyphenylene sulfide tape, fabric ornon-woven, and the like, and generally followed by another 1, 2, 3, 4, 5or more layers of matrix and particles. Symmetric application isintended to mean alternating layers of the above materials such as H, G,H, G, or H, H, G, G, H, H, G, G, H, H. Such fiber or fabric may bewetted prior to application either with an epoxy or polyester resin orsystem or the combination with glass and/or ceramic shapes.

[0028] Second Strata

[0029] The second strata of insulation of embodiments of my inventionmay include syntactic foams as discussed above, and may alternativelyinclude one or more layers of the insulation material or materials ofthe first strata coupled with the syntactic foam or other second stratainsulation. Or the second strata may include the material combinationsdescribed immediately above. In another embodiment, a second pipe orconduit spaced outside, or containing the first pipe or conduit, thesecond pipe may be encompass the first strata and a second insulationstrata material selected from one or more of syntactic foams asdiscussed herein, liquids, vacuum, gases (such as nitrogen or othergenerally inert gases or air and the like) or combinations thereof, allof which are intended to provide insulation to the pipe or conduit.

[0030] The second strata may include one or more of syntactic plasticfoam, such as polyethylene, polypropylene, polyurethane, polyvinylchloride, polystyrene, and the like, and such syntactic foams mayinclude discrete hollow or porous particles formed from anothermaterial, either organic or inorganic. Such second strata may be formedin one or more layers.

[0031] The second strata may also include one or more of silica, glassceramic or carbon fiber, tape or fabric (woven or non-woven), silica,glass ceramic or carbon fiber epoxy composites, silica, glass ceramic orcarbon fiber and other polymers.

[0032] The thickness of the second strata may be >0.1″, or >0.25″,or >0.5″, or >1″ or <10″, or <8″, or <6″. The number of layers may befrom 1 to 10 or more and all numbers in between.

[0033] Abrasion Resistant Coating

[0034] Optionally, one or more layers of a topcoat, such as EC-376F,manufactured by Industrial Environmental Coatings Corp of Pompano Beach,FL, may be used as the topcoat or abrasion resistant coating, generallyapplied to the outermost insulation strata.

[0035] EC-376F is described by the manufacturer to be a speciallyformulated high performance, 100% solids, flexibilized epoxy phenolicthat is said to demonstrate excellent adhesion, resistance to thermaland mechanical shock and excellent chemical and physical resistance in awide range of crude and refined petroleum products. It is furtherdescribed as a thick-film epoxy material that exhibits excellentperformance characteristics when evaluated against other thick-filmepoxy coatings in tthe following tests:

[0036] *Standard Atlas Cell Test (Modified NACE TMO 174-91)

[0037] *Pressurized Atlas Cell Test (Modified NACE TMO 174-91)

[0038] *Autoclave Test (NACE TMO 185-88)

[0039] *Impact Test (ASTM G 14-88)

[0040] *Abrasion Resistance (ASTM D 4060-90)

[0041] *Cathodic Disbondment (ASTM G95)

[0042] *Adhesion Pull-Off Strength (ASTM D4541-89)

[0043] *Flexibility (Modified CSA Z245, 20-M92)

[0044] *Hardness (Shore D)

[0045] *Electrochemical Impedance Spectroscopy (E.I.S.)

[0046] Epoxy coatings generally may not be suited for high temperatures(above 225° F.). Epoxy coatings may be generally low in adhesion(900-1000 psi to the substrate) where EC-376 has tested above 1800 psi.EC-376 exhibits improved permeability values over typical epoxycoatings. The chemical resistance of epoxy is generally good but dependson the type epoxy used.

[0047] Additionally or alternatively, the optional abrasion resistantcoating may be Ceram-Kote™ 54, manufactured by Freecom, Inc. Big Spring,Tex., USA, which is described as an epoxy ceramic. The coating isdescribed as an epoxy ceramic. The product may be considered to bedescribed in U.S. Pat. No. 4,968,538 and 4,789,567, both fullyincorporated by reference herein for purposes of US patent practice.

[0048] The optional abrasion resistant coating can be applied to theinsulation in 1, or 2, or 3 or 4 or more layers at a thickness of >1mils, or >5 mils, or >10 mils, or ≦40 mils, or ≦30 mils, or ≦25 mils, or≦20mils, or ≦15 mils. The number of coats or layers of this abrasionresistant coating material, as for the above insulation, may be morethan one, and up to 10 or more.

[0049] Other optional top coats are contemplated. As long as the coatingselected has substantially complete adhesion to the outermost insulationstrata, provides a desired protection of the insulation layer or layers,if necessary, and does not substantially impede the flow of product andmay enhance the flow, they will be among the coatings contemplated.

[0050] Pipes and Pipelines

[0051] Pipes and pipelines are contemplated as substrates to be coatedby the combination of insulation strata and optional abrasion resistantcoating. While generally including pipes of ≧2 inches (5 cm), or ≦48inches (232.2 cm), or ≦40 inches, or ≦30 inches (75 cm) in insidediameter (ID), other sizes are contemplated as well. The pipe willgenerally form some portion of a fluid delivery apparatus, such as apipeline, including pumps, manifolds, heaters production risers,drilling risers, Ts, elbows, instrumentation, down hole safety valves,packers, tubing hangers, injection mandrels, temperature measurementgauges, and the like. Pipe may be of any length, and when combinedthrough conventional means (welding, coupling), may form a pipeline,again of any length. The pipelines contemplated are used to transportfluids such as natural gas, crude oil, refined petroleum products (suchas gasoline, jet fuel, aviation gas, kerosene, heating oil, or bunkeroil) fluid chemicals, slurries, brine, and the like. While anenvironment for the coated and insulated pipe or pipeline may beunderwater, other uses are not precluded, such as underground, or aboveground in any application where maintanence of some or all of atemperature difference (ΔT) between product inside the pipe and theexterior environment is sought. The pipe may be steel or any type offerrous or non-ferrous metal, plastic fiber composites (such as“fiberglass” or carbon fiber composites).

[0052] In a further embodiment, at least a portion of the pipeline issubmerged in water. The water may be fresh, brackish or salt water. Thedepth may be 0.1 meter to 2 kilometers or even greater depths astechnology is available, are contemplated.

[0053] The combination of insulation and optional abrasion resistantcoatings as described above may be of any total thickness, controlled bythe application process and the desired control of product temperatureand the environment that surrounds the pipe or pipeline. The optionalabrasion resistant coating is described above, and each layer may beapplied in one or more coating passes or application layers. The amountof protection from the outside elements desired may be a considerationof the amount of insulation and or coating applied, the temperature andchemical makeup of the fluids to be transported, as well as the distanceto be transported. For instance product, e.g. crude oil, at 120° F. asreceived from the wellhead, knowing the desired exit temperaturetraveling through water at 50° F., for two miles, will require certainlevels of insulation, and the insulation may require a certain level ofthe optional abrasion resistant coating, both may be determined by thoseof ordinary skill in the art applying principles of fluid transport andthermodynamics. Also to be considered is the nature of the transportedfluid, for instance, if the product has a substantial portion ofconstituents that would crystallize (or form hydrates) or in another waycome out of the fluid at temperatures below the temperatures coming outof the wellhead, then the product must be desirably kept above thetemperature at which the crystallization would occur. Even if theproduct is substantially devoid of such constituents, but would rise inviscosity at temperatures approaching that of the (lower) ambientenvironment, it is advantageous to reduce or eliminate the viscosityrise. There may be other reasons or combinations of reasons to insulatepipes and pipelines, such uses are also contemplated.

[0054] Those of ordinary skill in the art will appreciate that aneffective amount of each of the insulation strata and the optionalabrasion resistant coating layer or layers will be applied to a givenpipe for specific service. Again, as above, the temperature differencebetween the environment and the fluid product (eg water temperature, andcrude oil temperature) as well as the temperature at which the fluidproduct is desired to be maintained or delivered, will be determinativeof the amount of insulation, thickness and/or number of insulationlayers, and optional abrasion resistant coating used. By an effectiveamount I intend that this include not only total thickness, but also aneffective number of layers making up the total thickness. The layers maybe equal or unequal in their thickness.

[0055] Fluids

[0056] While natural gas, natural gas liquids, and crude oil aredisclosed, any fluid, e.g. gas, liquid, slurry, are contemplated.

[0057] Other Pipeline Insulation

[0058] While the insulation described herein will generally suffice forrelatively long pipe runs and in water or other media, such as earth(burial) and air, that can be cold, additional insulation schemes may beused in addition to the insulation strata the pipe disclosed herein.

[0059] For instance, burial in a trench and/or burial or partial burialwith fine-grained bulk material such as sand, and/or coarse-grainedmaterial such as gravel as an addition to embodiments of my invention isalso contemplated. Among such techniques are those disclosed in GB 2 221873A (Wesminster Seaway Ans).

[0060] Other techniques such as pipe in a pipe, while generally beingless desirable as a sole insulation system than the insulation systemdiscussed herein, may be used in addition to or in combination with thedisclosed insulation.

[0061] Some insulation value may result from the optional abrasionresistant coating, the majority of the insulation value is expected tobe derived from the insulation of embodiments of my invention.

[0062] While I contemplate pipes or piplines with the insulationproximate the circumference of the pipe or pipeline (and optionally aprimer between the pipe surface and a first layer of insulation), andthe optional abrasion resistant coating proximate the of the insulationlayer or layers, other schemes are also contemplated. As possiblecombinations described below a)=insulation layer in a first strata,b)=abrasion resistant coating, c) insulation layer in a second strata,d) fiber or fabric Pi)=pipe's interior circumference, Po)=pipe'sexterior circumference, and η=a number 1 or greater.

[0063] Pi, a, b, or Pi, b, a, or Pi, a, b, a, or

[0064] Pi, a, a, .. . a^(η), b, b, . . . b^(η)

[0065] Or, Pi, a, a, . . . a^(η), b, or Pi, a, b, a, b or

[0066] b, a, Po, Pi, a, b or a, Po, Pi, a, b, or

[0067] a, a, . . . a^(η), Po, Pi, a, a, . . . a^(η), b, or

[0068] b, Po, Pi, a, b, or b, . . . b^(η), a, . . . a^(η), Po, Pi, a, .. . a^(η), b, . . . b^(η) or Po, Pi, b^(η), a^(η), or b, b, a, a, Po,Pi, or b, a, a, Po, Pi or b^(η), a^(η), Po, Pi, a^(η), b^(η), or b, Po,Pi, or b^(η), Po, Pi, or a, Po, Pi, a or a, Po, Pi, a^(η), or a^(η), Po,Pi, a, or a^(η), Po, Pi, a^(η). , Po, Pi, a, or Po, Pi, a^(η). c^(η),a^(η), Po, Pi, or c, a^(η), Po, Pi, or c^(η), a^(η), Po, Pi, a^(η), orc^(η), a^(η), Po, Pi, a^(η), c^(η), or Po, Pi, a^(η), c^(η), or Pi, a,d, c^(η)or Pi a^(η), d, c^(η), or Pi, a^(η), d^(η), c or Pi, a^(η), d, cor Pi, a, d, c or Pi, a^(η), d^(η), c or Pi, (a+d) ^(η), c or c, d, a,Po or c, d^(η), a^(η), Po or c^(η), d^(η), a^(η), Po, or c^(η), d^(η),a^(η), Po or c, (d+a) ^(η), Po, or c^(η), (d+a) ^(η), Po, or c, (d+a)^(η), Po, Pi, a, or c, (d+a) ^(η), Po, Pi, a^(η), or c, (d+a) ^(η), Po,Pi, a^(η), c, b.

[0069] Other methods of insulating pipe or pipelines known to those ofordinary skill in the art may be used in conjunction with the insulationstrata of the pipe as disclosed herein. Such other methods should beadditive to the techniques and materials (insulation) disclosed herein.At a minimum such techniques should not detract from the insulationprovided by the insulation described herein.

[0070] Exterior Pipe Coatings

[0071] Corrosion protection of an exterior or exterior surface of a pipeby any conventional means known to those of ordinary skill in the art,in addition to my disclosed insulation and optional abrasion resistantcoating on the interior and optionally on the exterior of the pipe, isalso contemplated.

[0072] Such exterior corrosion protection may include, but is notlimited to, adhesive and tape (e.g. vinyl or polyethylene) wrapping,epoxy powder coating, other powder coating, extruded plastic (such aspolyurethane, polyolefins, vinyl and the like), extruded elastomers(ethylene propylene rubber, butyl rubber, nitrile rubber,polychloroprene rubber and the like), liquid applied epoxy both byitself and in conjunction with woven or non-woven tapes or fabrics orpolymeric organics or inorganics, and combinations of these techniques.

[0073] Additionally, the application of the insulation layer or layers,preceded by an optional primer, and optionally covered by an abrasionresistant coating, to the exterior of the pipe, in addition to theapplication of a similar system on the interior surface of the pipe isalso contemplated.

[0074] Also contemplated are cement or cementitious compositions used onthe exterior of pipes or pipelines in conjunction with embodiments of myinvention disclosed herein.

[0075] Pipe Joining and Joint Protection

[0076] As pipe is joined by welding, coatings formed on the interiorsurface of the pipe prior to welding, may be degraded by the hightemperature of welding. To address such a problem, various measures havebeen proposed. Among these various measures are U.S. Pat. No. 5,547,228and a Continuation-in-Part of the '228 document, U.S. Pat. No.5,566,984, both fully incorporated by reference herein for purposes ofU.S. patent prosecution, which suggest a solution. These documentssuggest several constructions that are said to protect both the pipebeing welded and its coating. The cylindrical corrosion barrier for pipeconnections may be a non metallic material such as polytetrafluoroethylene (PTFE) which may also have fibers in the polymer matrix (suchas glass fibers). Use of such welding protection devices and methods, inconjunction with embodiments of my invention, are also contemplated. Wefurther contemplate that such a cylindrical corrosion barrier may be alength of pipe, similar in size and configuration (although small enoughto fit in the pipes to be welded) to the PTFE barrier, and such smalllength of pipe may be coated similarly to the pipe itself by methods andwith materials disclosed herein. That is, on its interior, an optionalprimer may be proximate the interior surface of the barrier covered withat least one layer of the insulation and optionally at least one layerof an abrasion resistant coating. Such a system will provide insulationat the weld lines where the pipe is joined.

[0077] Additional insulating layers of other materials such aspolyurethane, polyvinyl chloride (PVC), polystyrene and the like, eitherfoamed or non-foamed are also contemplated.

[0078] Other corrosion resistant coating or layers are also contemplatedincluding, but not limited to asphaltics, pressure sensitive adhesives,PVC, polyethylene, impregnated paper, epoxy powder and liquid applied,with or without an organic or inorganic tape or fiber, and the like.

PROSPECTIVE EXAMPLES Prospective Example 1

[0079] A 6 inch (15.24 cm) ID steel pipe is sand blasted with garnet toclean mill scale, dirt, grease and other contaminants from the steel.The grit so blasted on the interior surface creates a 1-4 mil anchorprofile to aid in adhesion of the primer and/or insulation layer to theinterior steel surface of the pipe. A primer such as EP-10, manufacturedby Morton, (Reading, Pa.), is applied at a thickness from 0.5 mil to 1mil and is cured by heat for 30 minutes to one hour at 300° F. Theprimer is applied directly to grit blasted steel surface prior to theapplication of the first insulation layer. The primer is spray appliedusing an automated coating lance that reaches from the entry end of thepipe to the far end. When the retraction of the lance begins, the primeris applied by pressure through a spray tip on the end of the lance at360 degrees to cover the interior surface at the thickness stated above.The pipe is heated to a steel temperature of 150° F. A coating lance isinserted through the pipe and 40 mils of ceramic insulation Ceram Cover®100 is applied using an airless spray tip that spins creating a 360°spray pattern. The density of the ceramic insulation, as determined byASTM D-792 is 0.41 g/cm³.

[0080] The pipe is then moved to a cure oven with a temperature of 160°F. -175° F., and remains in the oven at the temperature for 10 minutes.Then a coat of Enviroline ® EC-376 (Enviromental Coatings Corp., PompanoBeach Fla.) is applied to an additional (in addition to the thicknessesof ceramic insulation) thickness of 10 to 15 mils. After the abrasionresistant epoxy coating or top coating is applied and allowed to curefor 1 hour, a wet sponge holiday detection lance is inserted into thepipe which detects holidays or pinholes. If a pinhole is detected, thecoating lance is re-inserted to that portion or portions where thepinhole is detected and additional abrasion resistant epoxy coating isapplied.

[0081] Additional prospective examples are made to demostrate theeffectiveness of the application of multi-layers of the insulation. Theexamples represented in Tables II and IV are two different applicationsof insulation, and Table V represents bare steel with no coating,primer, or insulation.

[0082] This comparison is between a steel pipe insulated with 40 mils ofthe ceramic insulation in one layer (Table IV), and a similar steel pipeinsulated with 40 mils of the ceramic insulation but with four ten millayers (Table II). The assumptions, conditions and results are found inTables I-IV.

[0083] All examples have an initial oil temperature of 140° F. and areoperating in an environment of 36° F. water. The pipe is 6 inch. Withone layer of insulation at 40 mils thickness at a flow rate of 10,000barrels per day (bbl/day), the oil comes to 100° F. in a distance of4.56 miles. In the example with four ten mil layers (total again 40mils) of insulation the oil does not come to 100° F. until 17.11 miles,an increase over the single layer of 40 mils of over 275%. Also bycontrast, the uninsulated (bare steel pipe, Table V) pipe comes to 100°F. at (1.5 miles) In the tables which follow, the followingabbreviations are used: Outside diameter d₀ Inside diameter d_(i) crosssectional area A q Heat flow from oil through (insulated) pipe, inBTU/hr. P/L Pipeline T° F. Temperature, degrees Fahrenheit TiTemperature inside of pipe/insulation To Temperature on outside of pipe

[0084] Conclusion

[0085] The present invention has been described in considerable detailwith reference to certain versions thereof, other versions are possible.For example, while steel pipes insulated on their circumference fortransport of hydrocarbons have been exemplified, other uses are alsocontemplated. Therefore, the spirit and scope of the appended claimsshould not be limited to the description of the versions containedherein. TABLE I Oil Flow in Pipeline Pipeline: 6″ Oil-steel filmconductance, Uo-s 5 Btu/ft2, hr, ° F. d₀: 6.625 inches Water-steelconductance, Us-w 4 Btu/ft2, hr, ° F. d₁: 5.761 inches Steel thermalconductivity, ks 312 Btu/ft2, hr, ° F./in Length: 8 miles Oil specificheat; Ho 0.5 Btu/Lb, ° F. X-sect. Area: 0.1810186 Ft2 To, temperature ofoil Outer Surf. Area, S: 1.7344209 Ft2/Ft Tw, temperature of waterFluid: 40 API (6.87 Lb/gal) Fluid volume 0.181 Ft3 Flowrate: 10000BBL/Day 1.354 gallon (38.99287 Ft3/min) Fluid Velocity: 215.40812 Ft/minWeight w Flow Transit Time: 3.2682148 Hours Wt. Of 1-Ft. Section of Oil:9.3021101 Lb Oil Temp. @ Entry: 140° F. Outside Water Temp: 36° F.Internally CC Coated: 4 layers CC-Oil film conductance, Ucc-o 5 Btu/ft2,hr, ° F. 10 mils each Steel-CC conductance, US-cc 3.83 Btu/ft2, hr, ° F.CC-CC layer conductance, Ucc 0.667 Btu/ft2, hr, ° F. Diameters 5.741 d4(1^(st) layer) CC thermal conductivity, kcc 0.064 Btu/ft2, hr, ° F./in5.721 d3 (2^(nd)layer) 5.701 d2 (3^(rd) layer) 5.681 d1 (4^(th) layer)X-sect. Area: 0.1760261 Ft2 Fluid Velocity w/CC: 221.5176 Ft/min FlowTransit Time: 3.1780771 Hours Wt. Of 1-Ft. Sect. Of Oil: 9.045557 Lb

[0086]${{Where}\quad q} = \frac{{Sx}\left( {t_{0} - t_{w}} \right)}{{\frac{d_{o}}{d_{1}}\frac{1}{U_{{cc} - o}}} + {\frac{d_{o}}{2 \times k_{cc}}\log_{e}\frac{d_{i}}{d_{1}}} + {\frac{d_{o}}{U_{cc}} \times \left( {\frac{1}{d_{2}} + \frac{1}{d_{3}} + \frac{1}{\overset{\_}{d_{4}}}} \right)} + {\frac{d_{o}}{2 \times k_{s}}\log_{e}\frac{d_{o}}{d_{i}}} + {\frac{d_{o}}{d_{i}}\frac{1}{U_{s - {cc}}}} + \frac{1}{U_{w - s}}}$the  time  required  for  oil  temperature  to  drop  10^(∘)  F.  Δ  T × q = w × Ho × 10^(∘)  F.  

TABLE II CC Coated Pipe Output Results Oil Flow in Pipeline 4 Layers ofCC (Total thickness of 40 mils) 10 mils/layer 10,000 BOPD q = 0.3225″(Ti-To) Avg. q for Time for Cum Dishance T q @ T Temp Drop Temp DropTime In P/L ° F. Btu/Hr Btu/Hr Hr Hr Miles 140 33.5412 130 30.316131.9286 1.4165 1.4165 3.5657 120 27.0909 28.7035 1.5757 2.9922 7.5321110 23.8658 25.4784 1.7751 4.7674 12.0006 100 20.6407 22.2533 2.03246.7998 17.1167 90 17.4156 19.0282 2.3769 9.1767 23.0999 80 14.190515.8030 2.8620 12.0386 30.3042 70 10.9654 12.5779 3.5958 15.6344 39.355760 7.7403 9.3528 4.8357 20.4702 51.5284 50 4.5152 6.1277 7.3809 27.851070.1078 40 1.2900 2.9026 15.5818 43.4328 109.3311 38 0.6450 0.96759.3491 52.7819 132.8850 36 0.0000 0.3225 28.0473 80.8292 203.4669

[0087] Table III Oil Flow in Pipeline Pipeline: 6″, schedule 80Oil-steel film conductance, Uo-s 5 Btu/ft2, hr, ° F. OD: 6.625 inchesWater-steel conductance, Us-w 4 Btu/ft2, hr, ° F. ID: 5.761 inches Steelthermal conductivity, ks 312 Btu/ft2, hr, ° F./in Length: 8 miles Oilspecific heat; Ho 0.5 Btu/Lb, ° F. X-sect. Area: 0.1810186 Ft2 OuterSurf. Area: 1.7344209 Ft2/Ft Fluid: 40 API (6.87 Lb/gal) Flowrate: 10000BBL/Day (38.99287 Ft3/min) Fluid Velocity: 215.40812 Ft/min Flow TransitTime: 3.2682148 Hours Wt. Of 1-Ft. Section of 9.3021101 Lb Oil: OilTemp. @ Entry: 140° F. Outside Water Temp: 36° F. Internally CC Coated:1 layers CC-Oil film conductance, Ucc-o 5 Btu/ft2, hr, ° F. 40 mils eachSteel-CC conductance, US-cc 3.83 Btu/ft2, hr, ° F. CC-CC layerconductance, Ucc 0.667 Btu/ft2, hr, ° F. 5.681 d1 (1^(st) layer) CCthermal conductivity, kcc 0.064 Btu/ft2, hr, ° F./in X-sect. Area:0.1760261 Ft2 Fluid Velocity w/CC: 221.5176 Ft/min Flow Transit Time:3.1780771 Hours Wt. Of 1-Ft. Sect. Of 9.045557 Lb Oil: Externally CCCoated: 1 layers CC-Water film conductance, Ucc-w 5 Btu/ft2, hr, ° F. 20mils each (Estimated) 6.665 d3 (outer layer OD) Outer Surf. Area:1.74489029 Ft2/Ft

[0088] TABLE IV Internal CC Coated Pipe Output Results Oil Flow inPipeline One Layer of CC 40 mils/layer 10,000 BOPD q = 1.2082″ (Ti-To)Avg. q for Time for Cum Distance T q @ T Temp Drop Temp Drop Time In P/L° F. Btu/Hr Btu/Hr Hr Hr Miles 125.6535 130 113.5714 119.6124 0.37810.3781 0.9518 120 101.4893 107.5304 0.4206 0.7987 2.0106 110 89.407395.4483 0.4738 1.2726 3.2034 100 77.3252 83.3662 0.5425 1.8151 4.5690 9065.2431 71.2842 0.6345 2.4496 6.1661 80 53.1611 59.2021 0.7640 3.21358.0892 70 41.0790 47.1201 0.9598 4.1734 10.5054 60 28.9970 35.03801.2908 5.4642 13.7547 50 16.9149 22.9559 1.9702 7.4344 18.7142 40 4.832810.8739 4.1593 11.5937 29.1842 38 2.4164 3.6246 2.4956 14.0893 35.466236 0.0000 1.2082 7.4868 21.5760 54.3122

[0089] TABLE V Bare Steel Output Results Oil Flow in Pipeline 10,000BOPD Avg. q for Time for Cum Distance T q @ T Temp Drop Temp Drop TimeIn P/L ° F. Btu/Hr Btu/Hr Hr Hr Miles 140 374.6373 130 338.6145 356.62590.1304 0.1304 0.3192 120 302.5917 320.6031 0.1451 0.2755 0.6744 110266.5889 284.5803 0.1634 0.4389 1.0744 100 230.5460 248.5575 0.18710.6260 1.5325 90 194.5232 212.5346 0.2188 0.8449 2.0681 80 158.5004176.5118 0.2635 1.1084 2.7131 70 122.4776 140.4890 0.3311 1.4394 3.523560 86.4548 104.4662 0.4452 1.8847 4.6133 50 50.4319 68.4434 0.67952.5642 6.2767 40 14.4091 32.4205 1.4346 3.9988 9.7884 38 7.2046 10.80680.8608 4.8596 11.8954 36 0.0000 3.6023 2.5823 7.4419 18.2163

I claim: 1 A submerged pipeline insulated for retaining all or part ofthe naturally occurring temperature of oil, where the pipeline issubmerged in water at least 20° F. lower in temperature than an initialtemperature of said oil, comprising, a) a pipe; b) a first insulationstrata including at least three insulation layers formed on ancircumference of a pipe portion of said pipeline, said insulation layershaving an R value of one of ≧14 or ≦60 per inch, as determined by ASTMC-177-85, wherein the compressive strength of said first stratainsulation is ≧3500 psi, as determined by ASTM D-1621, and wherein saidinsulation layers are present on said inside circumference of said pipeat a total thickness of one of ≧25 or ≦60 mils, said insulation layersincluding an epoxy, substantially free of phenolics and said insulationlayers including one of ceramics, glass and combinations thereof, saidlayers being one of the same thickness or different thickness, saidlayers further include a layer or layers of fiber or fabric, said fiberor fabric selected from one of glass, carbon, silica, polyethlene,polypropylene, polyphenylene sulfide, polyphenylene oxide, orcombinations thereof, said fiber or fabric interspersed between at leasttwo of the insulation layers; c) a second insulation strata, said firstinsulation strata being spaced between said pipe and said secondinsulation strata, said second insulation strata including one or morelayers of one of urethane foam, syntactic urethane foam, syntacticpolyethylene, syntactic polypropylene, or combinations thereof, saidsecond strata having a thickness of one of >1 or <10 inches; d)optionally at least one abrasion resistant layer formed on the insidecircumference of said insulation, said abrasion resistant layer, ifpresent, is present at one of ≧10 or ≦15 mils, and said abrasionresistant layer including abrasion resistant particles, an epoxy resin,a hardener, and a diluent.
 2. An insulated pipe comprising: a)optionally at least one abrasion resistant layer; b) a first insulationstrata including ≧2 insulation layers including one of acrylics,epoxies, ceramics, glass or combinations thereof; c) a second insulationstrata including an effective amount of one of syntactic polyurethane,syntactic polyethylene, syntactic polypropylene, polyvinyl chloride,polystyrene, or combinations thereof; and d) a pipe.
 3. The abrasionresistant, corrosion resistant insulated pipe of claim 2 wherein saidpipe is part of a pipeline and wherein at least a portion of saidpipeline is submerged in water.
 4. The abrasion resistant, corrosionresistant, insulated pipe of claim 3, wherein said optional at least oneabrasion resistant layer may be present at one of ≧1 or ≦40 mils,wherein said first strata insulation layers are present at a total ofone of ≧2 or ≦120 mils.
 5. The abrasion resistant, corrosion resistantinsulated pipe of claims 4, wherein said first strata insulation has acompressive strength of ≧3000 psi, as determined by ASTM D-1621, andwherein said first strata insulation has an R value ≧50 per inch, asdetermined by ASTM C 177-85.
 6. The abrasion resistant, corrosionresistant insulated pipe of claim 3, wherein said insulation is presentin at least four layers, wherein said layers are one of equal or unequalthickness.
 7. The abrasion resistant, corrosion resistant insulated pipeof claim 3, wherein said first strata insulation is present in at leastthree layers, wherein said insulation may be an epoxy, substantiallyfree from phenolics, containing particles, said particles being one ofasymmetrical, symmetrical, amorphous, non-spheroidal, spheroidal, orcombinations thereof, and wherein said particles are one of ceramic,glass or combinations thereof; wherein said first strata includes atleast one layer of a woven or non-woven fabric, said fabric being one oforganic or inorganic, and wherein said first strata insulation has acompressive strength of ≧100 psi, as determined by ASTM D-1621, andwherein said insulation has an R value ≧10 per inch, as determined byASTM C 177-85.